MyService{
...
public void startListening(){

new Thread(new Runnable(){

 public void run(){
 PowerManager mgr = (PowerManager)c.getSystemService(Context.POWER_SERVICE);
 final WakeLock wakeLock = mgr.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "ListeningLock");

 new Thread(new Runnable(){

 public void run(){
   wakeLock.acquire()
   someClass.infiniteListeningLoop();
   wakeLock.release();
 }

 }).start();

 }).start();

}

}